Hmmmmm good question and I really dont know for sure but it pre dated Lindberg buy quite a while. Try asking here. http://www.scalemotorcars.com/ Greatest car model site there is. Doc.
Nope. Frog made the first plastic model kits of any kind, however they were AIRPLANES. The FIRST PLASTIC MODEL CAR was probably the PROMO '49 Olds 98 four-door sedan molded in acetate by Cruver (who manufactured most of the 1/72nd scale black acetate "spotter" model airplanes during WW2). First plastic CAR model KIT is probably debatable, but among the first had to be Gowland & Gowland's 1/32nd scale (later Revell) "Highway Pioneer" series in the early '50s. They were molded in warp-prone acetate, like the Frog airplanes. Hudson Miniatures kits from the late '40s of antique cars, were mostly wood, paper and wire but did introduce some plastic parts in the very early '50s. (Incidentally, these are the models a very tormented Joseph Cotton is building in the movie "Niagara" with Marilyn Monroe.) They was also a much more obscure early maker (whose name I can't recall) of kits of 1890-1900s (Duryeas and Seldens, etc.) cars that were composite wood and plastic. Monogram introduced their first acetate plastic cars, a 1/24 Hot Rod roadster, and a larger scale (1/20th?) Kurtis Kraft Offy midget racer around 1954, I think.